1. Field of the Invention
The present invention relates to a thermoplastic resin composition excellent in mechanical properties.
2. Description of the Related Art
A liquid crystalline polyester does not cause entanglement in a molten state because of the rigid molecular shape, forms a polydomain in a liquid crystal state, and exhibits a behavior in which the molecular chains orient remarkably in the flow direction by shearing at the time of molding, and is generally, called a liquid crystalline polymer (thermotropic liquid crystalline polymer).
For this specific behavior, a liquid crystalline polyester has an extremely excellent melt flowability. Depending on the structure, a liquid crystalline polyester has a high deflection temperature under load and a high enduring temperature (continuously usable temperature), such that neither deformation nor a blister is produced even in a molten soldering temperature of 260.degree. C. or more.
From the above, a resin composition including a liquid crystalline polyester filled with a fibrous reinforcement such as a glass fiber, an inorganic filler such as talc, and a heat stabilizer etc., serves as a material suitable for electric and electronic parts having thin or complicated form, and used for relay parts, a coil bobbin, a connector, a sealing of relay coil and IC, volume parts, a commutator, motor parts, etc.
Blended compositions of various liquid crystalline polyesters and thermoplastic resins have been examined for the purpose of improvement of melt processability, mechanical strength, etc.
For example, JP-A-56-115357 discloses that melt viscosity falls down by blending of a liquid crystalline polyester and other thermoplastic resins, and processability of a thermoplastic resin is improved.
JP-A-57-40551 discloses that the composition having an excellent mechanical strength is obtained by blending a liquid crystalline polyester and polycarbonate.
However, since different resins are generally incompatible, a mixture obtained by simple melt-kneading thereof will form a crude phase separation structure having a disordered sea-island structure. Physical properties such as mechanical strength are not sufficient in many cases, and inconveniences for the above-mentioned use might occur.